Project Overview

Multiple sclerosis (MS) is the most common cause of non-traumatic neurological disability, affecting 1 in 400 Canadian adults. It occurs when the immune system mistakenly attacks the brain and spinal cord, causing nerve damage. While current treatments reduce relapses, many patients still experience worsening disability over time. This progression is thought to be partly driven by chronic inflammation trapped within the brain, beyond the reach of existing therapies.

A special type of MRI-detected lesion, called a paramagnetic rim lesion (PRL), has been linked to this chronic inflammation and disease progression. PRLs form from a subset of new MS lesions seen on MRI with contrast dye, but it is unclear why some lesions evolve into PRLs while others do not. Understanding this process could help predict and prevent MS progression.

This study will investigate how immune cells in the blood and cerebrospinal fluid (CSF)—the fluid surrounding the brain and spinal cord—influence PRL formation. We will collect blood and CSF samples from MS patients when new lesions appear and use cutting-edge immune profiling techniques to study the types of immune cells present. Six months later, patients will undergo advanced MRI scans to see which lesions develop into PRLs. We will then identify immune cell signatures that predict which lesions do versus do not evolve into PRLs.

In addition to studying immune cells in living patients, we will also look at brain tissue from MS patients who have passed away. This lets us confirm which PRL-related immune cells are involved in long-term inflammation and shows us how they might damage the brain. By identifying immune signatures linked to PRL formation, this research could lead to better biomarkers to predict disease progression, guide earlier and more targeted treatments, and improve long-term outcomes for people living with MS.

Principal Investigator

Simon Thebault , The Royal Institution for the Advancement of Learning/McGill University